1. Field of the Invention
This invention relates to an apparatus for directly preparing a stock liquor from a powder container for supplying institutional dishwashing or washing machines, and to a method for directly preparing a stock liquor from a powder container for supplying institutional dishwashing or washing machines.
2. Discussion of Related Art
It is known that a stock liquor tank containing a detergent solution can be provided for supplying institutional washing or dishwashing machines with the detergent solution. The detergent solution is pumped as required from the stock liquor tank into the washing or dishwashing machines. To prepare the stock liquor from a powder or powder-form detergent, a metering unit is associated with the stock liquor tank. The powder is poured into the metering unit from a powder container or the powder container as a whole is introduced into the metering unit and slit open. Powder-form detergent is delivered in batches from the metering unit into a dispensing trough in which it mixes with inflowing water to form the stock liquor forming the detergent solution for the washing or dishwashing machine. The stock liquor is then directly introduced into the stock liquor tank. The detergent solution is removed from the stock liquor tank in accordance with the requirements of the particular washing or dishwashing process.
Filling the metering unit with the powder-form detergent is not without problems. It is frequently accompanied by dust emission which is unpleasant and a health hazard to the machine operator, particularly in the case of the strongly alkaline detergent powders typically used for dishwashing. Unwanted dust emission can occur both during the introduction of powder containers into the metering unit and during the pouring or scooping of powder from the container into the metering unit.
The holding capacity of known metering units for supplying known stock liquor tanks with powder-form detergent is typically 5 kg so that only 5 kg powder containers can be accommodated in the metering units. In addition, the powder is normally removed from the metering units and the powder/water mixture delivered to the stock liquor tank under the effect of gravity. Accordingly, the metering units are normally arranged above a stock liquor tank. This prevents the holding capacity of the metering units from being increased as required unless holders of complicated construction are provided for the metering unit.